Air-pump



S. G. SKINNER.

AIR PUMP.

APPLICATION FILED JUNE 28, 1919.

1,327,783. Patented Jan. 13,1920.

v STATES PATENT ornicn.

' STEPHEN G. SKINNER, or CHICAGO, I'LLmoIs;

IR-ruler.

To all whom it may concern:

Be it known that'I, STEPHEN G. SKINrInR,

a citizen-f the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented a certain new and useful Improvement in Air-Pumps, ofwhich the following is a. full, clear, concise, and

' exact description, reference being had to the accompanying drawings, forming a part of this-specification. v

Myinvention-relates to air pumps, particularly to that class of air pumps which a are employed for inflating pneumatic tires,

and briefly stated, the ob ects of my inven-. tion are First: The provision of a pump of this class in which the piston and valve elements are so arranged that the pump iscapable of rapidly performing its intended function when properly operated, due to the fact that.

before each downward or compression stroke that portion of the pump cylinder below, or

ahead, of the piston, is completely filled with air at atmospheric pressure;

Second: The provision of a pump of this class having a valved piston, the valve element of which is in the form of a flat disk of leather orsimilar material, which is entirely inclosed within and protected by the other parts of the piston; p

Third: The provision of a valved piston comprising an extremely small number of parts, which are capable of being easily and economicall manufactured and assembled;

' Fourth:

which may be entirely of drawn' or pressed metal; and

Fifth: The provision of a pump of this .class provided with a foot piece hingedlymounted on the pump base,'which base is so" formed that it coeperates to lock the foot piece in its down position.

v view of the pump piston;

he provision of a pump c prising a valved piston the metallic parts of Specification of Letters Patent. Patented' an. 13, 1920. Application filed June 28, 1919. Serial No. 307,331. v i

of. the male element of the piston; F ig.-5 is a- .top plan viewof the maleele ment of the piston, with the upper and lower,

metal member which constitutes the bottom parts thereof assembled and 'securedtogether.

Fig. '6 isian axial sectional view. of the pressed metal member which constitutes-the female element of the piston; I Fig. 7 is a plan view of the under side of the part illustrated in Fig. 6; and

Fig. 8 is a sectional view taken on line 8.8 of Fig. 1, this view illustrating the several parts in substantially their normal lar parts throughout the several views.

iReferring first to Fig. 1, the pump there shown comprises the tube or cylinder 10, the I upper end of which is provided with a cap 11 apertured at 12L The lower end of the tube is screwthreaded or-otherwise suitably secured in a cast metal base 13, which is suit ably drilled and tapped, as shown, to provide a passage between the lower end of the tubeand a nipple 14:, which in turnispro- *vided with the usual hose 15 adapted to be attached by a coupling 16 to the, valve of a pneumatic tire. At 17 is illustrated the piston rod, which has a sliding fit ,in the cap 11, and is provided with an o erating handle 18. As thus far described t e parts shown are 'conventionahand may be of any suitable form. a

'At its lower end the piston rod is provided with a valved piston, the several parts of which are illustrated in detail in Figs. 2

to 7 inclusive. Briefly, this piston comprises four principal parts, to-wit, a male element,

a female element, a leathe'rfcup washer, and

a valve member in the form of a leather disk. The male element comprises two ressed metal members 19. and 20. The memer 19 comprises a disk-like portion ,19,

from which is struck a hollow central boss 19", which is internally screwthreaded to' receive theexternally threaded lower end of the piston rod 17 An aperture 19 is punched in the disk portion 19. The male member 20 is hollow, and comprises the exi low the piston shall be completely filled with ber 19. The members 19 and20 are secured together by pressing portions of the metal of flange 20 down on the member 19 at a plurality of points 20, as is clearly shown in-Figs. 2 and 5.

The female element con'slsts of a cylindrical pressed metal member 21, open at its upper end and internally threaded to receive the externally threaded lower end of the male member 20. The bottom wall of the female element has a boss 21 struck upwardly therefrom, forming an annular channel between the boss and the inner cylindrical surface of the female element. A plurality of apertures 21, 21 afford communication between said annularch'annel and the. bottom of the female element.

Securely clamped between the male and female elements 20 and 21 is a leather cup washer 22, there being an annular space 23 between the cup washer and the outer cylindrical surface of the female element. Loosely mounted in the chamber formed between the bottom of the female member 21 and the lower end of the male member 20 isthe valve element which is. in the form of a leather disk 24, normally resting on the boss 21, said leather disk being of a diameter considerably less than the inner diameter of the fe-v male element 20;

In the operation of the pump, on the up stroke of the piston air enters the aperture" 12 in, the cylinder cap 11, and passes from the space above the piston tothe space below the piston. space above the lpiston to the space below the piston may ta e two paths. Some of the air may pass around the outside of the downwardly facing cup washer 22. However, practically all 'of the air takes a ath which on the upward stroke of the piston is entirely unobstructed. The. air passes through the aperture. 19 into the hollow male element. of the piston, thence through aperture 20 around the edges of the leather valve member 24, which is resting in the position shown in Fig. 2, and out through the apertures 21?. This unobstructed path insures that, prior to the beginning of the downward stroke of the piston, the space beair,-making the o eration of the pump extremely rapid. in, the downward movement of the pump piston compression below thepiston causes the disk 24 to seat tightly against the bottom of the male member 20,

effectually closing the aperture 20 and preventing the escape of air under pressure through the piston. At the same timethe air under pressure filling the annular space 23 forces the on washer tightly against the inner. surface 0 the pump. piston and prevents the escape of pressure around the piston.

The feet piece'25 is in the form. of a sub The air in passing from the reciprocated in sai stantially U-shaped bail of. spring metal, the legs of which are turned inwardly at 26, 26 and engaged in a transverse bore 27 in the base 13. A pair of substantially-horizontal shoulders 28 and 29 are formed integral with the boss 13,, there being a groove between these shoulders, as shown. When the 'bail or foot piece is moved from the raised position shown in dotteddines' in Fig.

, 1 to the full line position, the ends of the bail move outwardly, as indicated in dotted lines inFig. 8, to permit the legs of the bail to pass'over the shoulder 28 and snap into the groove between the shoulders28 and 29.

The foot piece is thus held in its down position until suflicient force is applied thereto I to cause the legs of the bail to snap over the wardly projecting boss coiipeiating with the threaded lower end of the piston rod, an externally threaded hollow cylindrical member having a centrally apertured bottom wall and an upper flange which embraces and. is secured to thev disk member, said female element comprising a hollow cylindrical 'member internally threaded to receive the externally threaded cylindrical portion of the male element,'and provided with a bottom wall having an upstanding central boss, an aperture in said last-mentioned bottom wall adjacent said last-mentioned boss, and a leather disk valve of less "diameter than the inside diameter of the female element, said disk valve being normally freely disposed on said last-mentioned boss, and adapted to close the aperture in the bottom of the male. element when the piston is on its down stroke.

2. In an air pump, the combination with a tube or cylinder exposed to the atmosphere at its upper end, a iston rod adapted to be 5 cylinder and provided at its lower end with a valved piston, comprising a hollow externally threaded cylindricalmale element and a hollow cylindrical internally threaded female element Icooperating therewith, an annular shoulder on the hollow male element, a downwardly facing cup washer clampedbetween said shoulder and the upper end of the female element, a centrally apertured bottom wall for said male element, a bottom wall for the female element provided with a centrally disposed upstanding boss, an aperture in the bottom of the female element adjacent said boss,'and a leather disk valve, the diameter of which is less than the inner diameter of I said female element, said disk valve being freely disposed between said bottom walls, normally resting on said upstanding boss and adapted to close the central aperture in the bottom of said male element when the piston is on its down. stroke.

3. In an air pump, the combination with a tube or cylinder exposed to the atmosphere at its upper end, a piston rod adapted to be reciprocated in said cylinder and provided .at [its lowerend with a valved piston comprising a downwardly facing cup washer and metal piston elements which provide boss, means permanently affording communication between the upper chamber and that portion of the cylinder above the piston,'and aleathe'r disk valve freely disposed in the lower chamber, said disk valve being normally disposed on said boss,-but adapted to close the central aperture in thewall between said chambers when the piston is on its down stroke. I v

. 4. In an air pump, the combination with a tube or cylinder. exposed to the atmosphere at its upper end, a piston rod adapted to be reciprocated in said cylinder and provided at its lower end with a valved piston comprising a downwardly facing cup washer and metal piston parts providing an inclosed chamber, a central aperture in the top wall of said chamber, through which communication, with the atmosphere is establish'ed, an upstanding central boss carried by the bottom;wall of said chamber, an aperture in said bottom wall adjacent said disk, and a leather .disk valve freely disposed in said chamber, normally resting on said upstanding boss, but adapted duringthe downward movement of the piston toclose the aperture in the upper wall-of said chamber. 7

5. An air pump comprising a cylinder, a

piston adapted to be reciprocated in said cylinder, a base in which the lower end of said cylinder is secured, a bore in said base on one side of said cy1inder,- a foot piece in.

the form of aU-shaped bail of spring metal,

having inturned' 'ends engaging in said transverse bore, together with upper and lower horizontal shoulders formed on the sides of said base, providing between them.

a depression into which the legs of said U-shaped bail member snap when the bail is moved into a plane parallel with the bottom of the base.

In witness whereof, I hereunto subscrib my name this 26th day of June, 1919.

STEPHEN G. 'SKINNER.

Witnesses:

ROBERT F. BRACKE, A. G. MCCALEB. 

